KCET2026PhysicsAtomic Physics
An electron transition takes place from excited state to ground state in hydrogen atom, then
Options
- AIts kinetic energy increases but potential energy and total energy decrease
- BIts kinetic energy, potential energy and total energy decrease
- CKinetic energy decreases, potential energy increases but total energy remains same
- DKinetic energy and total energy decrease but potential energy increases
Correct answer
A. Its kinetic energy increases but potential energy and total energy decrease
Step-by-step solution
The total energy of an electron in the n -th orbit of a hydrogen atom is given by E = - 13.6 n^2 eV. The kinetic energy is K = -E = 13.6 n^2 eV. The potential energy is U = 2E = - 27.2 n^2 eV. When the electron transitions from an excited state to the ground state, the principal quantum number n decreases. As n decreases, the value of 1 n^2 increases. Therefore, the kinetic energy K increases. Since the total energy E and potential energy U are negative and their magnitudes increase, their actual values become more